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The re-stacking of graphene sheets leads to the far lower areal capacitance and energy density of the graphene-based micro-supercapacitors (MSC) than the expected. Herein, to solve this issue, a novel 0D/2D porous carbon integrated architecture (PC-IA) is ingeniously in-situ constructed by a two-step fabrication strategy, which is realized by the synthesis of 0D/2D TiC integrated architecture in a molten salt-containing Ti environment based on graphene nanosheets (GNS) as the template followed by high-temperature chlorination. Interestingly, the newly synthesized PC-IA shows huge advantages compared with the original GNS, such as higher specific surface area, more abundant porosity, better wettability to electrolyte and more effective ion channels in the c-axis direction, etc. As a result, when PC-IA is used as the electrode material, the fabricated MSC exhibits excellent electrochemical performances, such as ultrahigh areal capacitance of 70.12 mF cm−2 and high energy density of 9.48 μWh cm−2. Moreover, the fabricated MSC also behaves excellent mechanical flexibility and can be easily adjusted in the voltage and capacitance by connecting multiple MSC devices in series and parallel. Hence, this work opens up a new way for the reasonable design of carbon-based electrodes, which has broad application prospects in various flexible/wearable electronic devices. [Display omitted] • A unique 0D/2D porous carbon integrated architecture (PC-IA) is first synthesized. • The PC-IA behaves high specific surface area and effective ion channels. • The micro-supercapacitor (MSC) is fabricated by mask-assisted vacuum filtration. • The PC-IA-based MSC exhibits ultrahigh areal capacitance and energy density. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new strategy was developed to prepare graphene sheets with tunable layer-number. • Sieving performance of membranes assembled from the graphene sheets was studied. • The membranes assembled from thin graphene sheets behaved better sieving performance. • An insight into optimizing the nanochannel structure in the membrane was proposed. Graphene oxide (GO)-based membranes have attracted extensive attention in water purification but still face great challenge due to their poor service life. To overcome this issue, weakly oxidized graphene nanosheets have been chemically exfoliated from natural graphite via a newly-developed strategy for preparing layer-tunable graphene. When an 80 μm-thick graphene membrane is assembled from the graphene nanosheets with an average layer number of 3, it exhibits a high rejection rate of 99.9 % for Rhodamine B and a water flux of up to 3452.6 L m−2 h−1 bar−1. This should be ascribed to the unique hierarchically nanochannel structure within the membrane. This finding may provide a new insight into the design and fabrication of the thick membrane having excellent sieving performance. Furthermore, the rejection rate of RB can be maintained at 99.9 % even after 24 cycles of filtrations, demonstrating a superior service performance for the membrane. [ABSTRACT FROM AUTHOR]

• A green and environmentally friendly chemical exfoliation method was developed. • Oxalic acid is used for the first time alone for chemical intercalation exfoliation of natural flake graphite. • No water-washing and effluent-treatment are involved during the whole chemical exfoliation process. • The 9-μm-thick-graphene film exhibits excellent electrical conductivity (5.05 × 105 S/m) and EMI shielding property (53.9 dB). The environmentally friendly preparation of graphene remains a great challenge. Herein, a novel and green preparation method for graphene has been developed. Graphene sheets were successfully exfoliated from graphite by intercalation and decomposition of oxalic acid for the first time. The whole chemical exfoliation process does not involve any waste liquid disposal, and, more importantly, the decomposed products by oxalic acid are CO 2 and H 2 O, respectively, demonstrating that the exfoliation method is environmentally friendly. The obtained graphene sheets exhibit high-quality and large-size with a yield of about ∼ 100%. The prepared graphene film exhibits excellent electrical conductivity (5.05 × 105 S/m) and EMI shielding property (53.9 dB with a thickness of 9.0 μm), suggesting a great prospect for miniaturized electronic devices and flexible wearable applications. [ABSTRACT FROM AUTHOR]

• A novel two-step microwave irradiation strategy for preparation of graphene with high-efficient is proposed. • No water-washing and effluent-treatment are needed during the whole preparation process. • The exfoliation yield of graphene is about 100%, including 66% of graphene sheets ≤5 layers. • The average area size of graphene sheets is up to 256.8 μm2. • The conductivity of the prepared graphene film can reach up to 2.03 × 105 S m−1. Scalable preparation of graphene with both large size and high quality is an important prerequisite for fully realizing its commercial use. Herein, we propose a high-efficient route for preparing few-layer graphene, in which the chemical exfoliation of graphite to ~100% few-layer graphene can be realized within only about 15 min by using a novel two-step microwave irradiation strategy. The as-obtained graphene sheets behave a few-layer feature (average layer number ≤5 layers) and possess large size (the average area size is up to 256.8 μm2). The graphene film prepared from the obtained graphene sheets exhibits an excellent electrical conductivity of up to 2.03 × 105 S m−1, among the highest ones reported so far for the graphene, suggesting the high quality of the prepared graphene. Most importantly, no water-washing and effluent-treatment are needed during the whole preparation process, which will greatly reduces the consumption of water resource and alleviates the environmentally detrimental impact caused by the effluent of used chemicals compared with those conventional chemical exfoliation routes. Benefiting from its simplicity, high-efficiency and high-quality, the present method will show great promise for the mass production of high-quality graphene sheets. [ABSTRACT FROM AUTHOR]